I try to live 5 miles or so from work. 10 round-trip a day, plus a little extra for errands (I never learned to drive) is enough cycling for me. I can do it in about half an hour at an easy and relaxed pace and during the winter it’s short enough to just walk if it’s snowy/icy.

But I know people who do 25 miles each way by bike for their daily commutes. Just depends how much you care about it and what you’re willing to sacrifice to do it.